it's not that difficult to do if you have the grades. having a certain number of credits is just a technical detail that varies from school to school. about half of the t14 takes transfer students who started PT. i have no idea about the rest of tier 1, but those with PT programs, such as my own school, could care less. usually this information is available on each school's web page.
as a side note (and i'm sorry to tell you this), but if you started PT, NYU is out of the question. fordham, which has a PT program, shouldn't be a problem.
also, don't go to a school you don't want to be at with the intent of transferring. the posts on this thread are absolutley correct about that.